Attachment for circular knitting machine



April 30, 1968 A. J. WILLIAMSON ETAL 3,380,256

ATTACHMENT FOR CIRCULAR KNITTING MACHINE Filed Oct. 24, 1965 3Sheets$heet 1 ANDREW JOHN WILLIAMSON, WILLIAM PORTER CHESNUTT,JR.

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A ril 30, 1968 A. J. WILLIAMSON ETAL ATTACHMENT FOR CIRCULAR KNITTINGMACHINE Filed Oct. 24, 1965 Sheets-Sheet 2 a I IIIIIIIIIIII I 'f\ I W22v f ,4? FIG. 2

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ATTACHMENT FOR CIRCULAR KNITTING MACHINE 3 Sheets-Sheet 5 Filed Oct. 24,1965 wwm I mw INVENTORS ANDREW JOHN WILLIAMSON, WILLIAM PORTER CHESNUTT,JR.

BY ATTOJP/VE/ United States Patent 3,380,266 ATTACHIVIENT FOR CIRCULARKNITTING MACHINE Andrew John Williamson, 213 Circle Drive, SW., andWilliam Porter Chesnutt, Jr., 503 Linden Circle, NE., both of Athens,Tenn. 37303 Filed Oct. 24, 1965, Ser. No. 504,656 1 Claim. (Cl. 66150)ABSTRACT OF THE DISCLOSURE The present disclosure describes a pull downmechanism for a circular knitting machine, causing the stitches to bepulled down from the sinkers, minimizing the possibility of theformation of irregular or skipped stitches or the like. The knittingmachine is provided with a delivery cylinder which carries an upwardlyoutwardly flaring portion having a plurality of spaced verticallyextending shed bars.

This invention relates to a circular knitting machine, and moreparticularly to a fabric pull down mechanism for a circular knittingmachine.

Still more particularly, this invention relates to a circular knittingmachine having a fabric pull down attachment to assure that stitcheswill be pulled from the sinkers, thereby to minimize the posibility ofthe formation of irregular or skip stitches, jams or the like.

This invention further relates to a pull down attach ment for aconventional circular knitting machine for assuring a steady,progressive feed of the fabric which has been knitted, which feed isindependent of the length or weight of the knitted increment.

The invention further relates to a knitting machine device having anovel shedding attachment to assure uniform tension of the knittedfabric as the stitches are formed.

Accordingly, it is an object of this invention to provide an improvedcircular knitting machine and attachment therefor.

A further object of the invention is to provide a dependable andautomatic mechanism for assuring a continuous and progressive feed ofknitted fabric through the cylinder of a conventional circular knittingmachine, whereby there is no tendency for the stitches to hang on thesinkers and the tension on the fabric at the knitting station is at alltimes uniform, to assure the formation of stitches of a desired size,independent of the weight of the fabric which has been formed and fedthrough the throat of the knitting machine.

To attain these objects and such further objects as may appear herein orbe hereinafter pointed out, reference is made to the accompanyingdrawings, forming a part hereof, in which:

FIGURE 1 is a perspective view of a needle cylinder and associatedmechanism including the attachment of the present invention, withcertain parts of the knitting device being omitted for clarity.

FIGURE 2 is a magnified vertical section taken on the line 22 of FIGURE1;

FIGURE 3 is a schematic developed view of the cam track operating thepull down device;

FIGURE 4 is a horizontal section taken on the line 44 of FIGURE 2;

FIGURE 5 is a horizontal section taken on the line 5-5 of FIGURE 2.

In accordance with the invention, 10 represents a conventional cylinderof a circular knitting machine, the illustrated cylinder being of thetype frequently employed for the fabrication of hosiery or the like.While the present invention is illustrated in conjunction with acylinder of this type, it will be readily recognized that the inventionis not limited in its use to hosiery knitting machines.

Since the knitting machine proper is in all respects conventional, thepresent invention residing solely in the pull down attachment and itscombination with the knitting machine, only an abbreviated descriptionof the standard knitting machine components Will be undertaken.

The cylinder 10 includes the usual vertical slots 11, slidablysupporting the needles 12 (see FIGURE 2). In the usual manner, the upperedge of the cylinder 10 is formed with radially directed sinker guideslots 13, within which the sinkers 14 are radially slidably carried.Sinker guide ring 15 is movably mounted on the upper end of the cylinder10 and incorporates the usual sinker control mechanism for effecting theinward and outward radial movement of the sinkers 14 in timed relationto the upward and downward movement of the needles 12 for the formationof the stitches which comprise the fabric.

It will be understood that the mechanism for actuating the sinker guidering 15 through the control bracket 16 has been omitted from thedrawings, for simplicity. Similarly, it will be understood that thedrawings do not include the conventional yarn feed fingers which arenormally located at the knitting station S.

The knitting cylinder 10, at a lower portion thereof, is provided with adrive gear portion 17 for engagement with the usual cylinder drivemechanism.

In accordance with the invention, a delivery cylinder 20 is co-axiallydisposed within the knitting cylinder 10,

' the upper end 21 of the delivery cylinder being provided with anoutwardly flaring receiver portion 22, the receiver portion beingdisposed adjacent the throat area T of the knitting cylinder. As bestseen from FIGURE 2, the receiver portion 22 comprises generally aninwardly tapered annulus defined by the annular wall portion 23. Thedelivery cylinder is provided with a plurality of vertically directedslots 24, which slots house and guide the shed bars 25, next to bedescribed, for vertical reciprocatory movement within the deliverycylinder.

The shed bars 25 are generally flat in cross-section and includeelongated body portions 26, slidably received within the slots 24. Thebody portion 26 of the shed bar is recessed, as at 27, to define arectangular cutout, said cutout including a vertically extended slideportion 28.

The delivery cylinder 20 includes an annular portion 29 having aninwardly directed flat surface 30 hearing against slide portions 28 ofthe shed bars, to guide the latter against canting during verticalshifting movement within the cylinder.

The upper ends 31 of the shed bars are bent outwardly to conform to theinclination of the annulus 23 at the upper end of the delivery cylinderand, as Will be seen from FIGURE 2, in the lowered position of the shedbars, the upper end portions lie substantially flat against this annularsurface. The lowermost ends 32 of the shed bars are directed radiallyoutwardly, projecting beyond the delivery cylinder.

A collar 33 is made fast, as by bolts 34, to the lower end of thedelivery cylinder, the collar including vertical slots 35 through whichproject the radially extending portions 32 of the shed bars 25.

The shed bars are biased to a normally downward position by an annulargarter spring 36, which may comprise a single annular member or aplurality of individual coil springs, or any other suitable arrangementfor downwardly biasing the portions 32 of the shed bars. In theillustrated embodiment, the spring 36 outwardly laps the surface of thecollar 33, the spring being fastened to the collar at spaced portions 37by bolts or other suitable fasteners.

The points 37 are located at a level below the normal lowermost positionto be occupied by the projecting portions 32. of the shed bars, so thata downward biasing force will always be exerted against these portionsby the spring. The spring 36 is disposed over the upper surface 32a ofthe projecting portion 32, said portion 32 being preferably providedwith a retaining pin 38 to maintain the spring in the desired position.

The upward and downward reciprocating movement of the shed bars iseffected by an annular cam member 39 which surrounds the rotatingdelivery cylinder and which bears against the under surface 32b of theradially projecting portions 32 of the shed bars. The annular cam 39 isgenerally cylindrical in conformation and includes an upwardly directedriser or tooth portion 40 (see FIG- URES 2, 3, 4) and an extended flator dwell portion 41.

In operation, the cam remains in fixed position while the deliverycylinder rotates. To block the cam against rotation with the deliverycylinder, the cam is provided with an offset finger 42, including adownwardly directed end portion, which portion lies in the path of astop 43, made fast to some portion of the base plate or frame of theknitting machine. Optionally but preferably, the position of the stop 43may be varied so as to vary the position of the tooth 40 with relationto the fixed knitting station S, so that the timing of the lift and dropof the shed bars may be carefully and adjustably coordinated with theother knitting operations.

While in the illustrated embodiment, the cam 39 is shown to have onlyone rise portion 40, it will be readily understood by those skilled inthe art that more such portions may be provided, preferably inaccordance with the number of knitting stations.

Each of the shed bars is provided substantially throughout its entirelength with a series of gripper means for the tubular knitted fabric,for advancing the same downwardly through the delivery cylinder. In theillustrated embodiment, these gripper means comprise short pointed barbs44, spaced along the length of the shed bars, each of said bars beingprovided with a series of barbs 44a in the area of the throat portion.

The barbs are directed both radially inwardly and downwardly, and itwill be evident from this orientation that as the shed bars are moveddownwardly, the barbs will engage the fabric and draw the samedownwardly an increment which is dependent upon the throw or extent ofthe downward movement of the bars. Since the fabric is tensioned by thedownward movement of the bars, the barbs will not be released from thefabric while the bars remain in downward position, ie as they traversethe dwell portion 41 of the cam. However, by reason of the downwardinclination of the barbs, they will be released from the fabricimmediately as the shed bars are raised by the cam tooth 40.

The operation of the device will be evident from the precedingdescription. The knitting cylinder 10, carrying the knitting needles andsinkers, is rotated in the usual manner, with the knitting needles andsinkers being selectively shifted inwardly and outwardly adjacent theknitting station S by the usual needle and sinker cams to knit thefabric. As the cylinder 10 and the connected delivery cylinder 20 arerotated, the tubular knitted fabric is fed through the throat area T andinto the interior of the delivery cylinder. As the delivery cylinder 20is rotated, the lower or follower surface 32b of the extensions of theshed bars are progressively wiped over the upwardly di- 4 rected surfaceof the annular cam 39. The spring 36 assures that such follower portionwill be in constant contact with the said cam surface.

In FIGURE 2, the righthandmost shed bar is depicted in its downwardmostposition against the flat or dwell portion 41 of the cam 39, whereas thelefthandrnost shed bar is disclosed in an elevated position atop thetooth 40 of the cam.

As will be best seen from the developed view of FIG- URE 3, all the shedbars but one, in the illustrated embodiment, are disposed generally atthe elongated dwell portion 41, whereas a single shed bar is shown atthe apex of the tooth 40. Under ordinary circumstances, it will bepreferred to so coordinate the position of the tooth and, hence, of theshed bars, that the bars are lifted just prior to entering the knittingstation S and are lowered directly after passing said knitting station.

As will be readily recognized, the position of the tooth 40- withrespect to the knitting station may be varied merely by releasing andreadjusting the position of the stop 43, which is fixed with respect tothe roating delivery cylinder.

While the primary utility of the device will be realized when the shedbars descend immediately after passing the knitting station, thusassuring that the loops will be completely shed from the sinkers, itwill be understood that the positioning of the cam may be employed in avariety of ways, for instance as a means for pre-tensioning the fabricduring the formation of loops, thus to control the size of the loops.

From the foregoing description, it will be evident that the deviceassures a continuous, even fiow of fabric knitted at a knitting stationor stations, downwardly through a delivery cylinder.

The shed bars act positively to urge the knitted fabric downwardly,thereby assuring that the same will be shed from the sinkers.

The adjustability of the cam mechanism to permit facile variation of thetiming of action of the shed bars may, in addition, be used to vary theknitted texture, as desired, and to assure optimum operation of thedevice.

We claim:

1. In a circular knitting machine of the type which includes a needlecylinder having a top throat portion rotatable about a vertical axis andcarrying vertically movable needles, sinkers mounted between saidneedles for movement toward and away from the axis of said cylinder, themovement of said needles andsinkers being coordinated as said cylinderis rotated past a knitting station, thereby to form stitches at a throatarea of said cylinder, a feed apparatus comprising a delivery cylinderconcentrically positioned within said needle cylinder, said deliverycylinder including an enlarged upwardly flaring neck portion adjacentsaid throat area, vertical guide means formed on the interior sides ofsaid delivery cylinder, vertical rectangular cross-section shed barsmounted on said guide means for vertical reciprocatory movement relativeto said delivery cylinder between raised and lowered positions, saidshed bars including downwardly and inwardly sloped portions in the areaof said enlarged neck portion, inwardly and downwardly directed grippermeans formed on said bars for gripping fabric in said throat area anddelivery cylinder during downward movement and in the lowered positionof said bars, and releasing said fabric as said bars move from loweredto raised position, cam follower portions on said shed bars andstationary cam means positioned to engage and vertically reciprocatesaid follower portions, said cam means and follower portions beingcoordinated to locate said shed bars in raised position just prior tosaid knitting station and to locate said bars in lowered position whensaid bars are roated past said station, said delivery cylinder at itslower end being provided with a circular collar and said shed bars beingprovided with outwardly extending radially projecting portions and acircular spring extending around and above said portions below saidcollar and retaining pins extend- 808,784 1/ 1906' Steber 66150 ingupwardly from said outwardly extending portions to 920,671 5/1909 Scottet a1 66 150 hold said spring in position. 2,3 5, 98 4/1944 Bromley etal 66-150 3,003,342 10/1961 Kent et a1. 66150 References Cited 5 UNITEDSTATES PATENTS FOREIGN PATENTS 433,251 7/1890 Meir 66-150 8781161 9/1942France 751,213 2/1904 Steber 66150 801,930 10/1905 Steber 66-450 W.CARTER REYNOLDS, Primary Examiner.

